Don’t fear Bruins fans, the Boston Bruins still hold his rights, this move is a deadline rental move for Niagara, a team expected to compete for the OHL Championship this season. Brassard is a 2017 7th round selection of the Vancouver Canucks, who will also retain his NHL rights. Moore is draft eligible for the 2020 NHL Entry draft, helping Oshawa solidify next years team while maximizing return for players not expected to return. For Niagara, this trade bolsters an already formidable roster expected to perform well this season.

It's pretty standard in the ohl to trade a star player for a couple young players and a boatload of draft picks especially 2nd rounders. Some of those picks will be traded multiple times before the actual selection is made. I don't think 1st round picks can be traded but not sure about that.